Interesting composite rocks, you've found there. I wonder what processes produced those, but am not much of a geologist.
Have you ever found petosky stones? My family used to go camping near Luddington, MI every year and we would look for petosky stones on both sides of the lake. They're getting to be a lot more rare than they once were.
I have a couple that I collected from a beach near Petoskey several years ago! These are the three that I found
Not the finest specimens, but I love that I found them myself.
Nice! I think the largest I ever found was maybe an inch long.
I found these early in the spring not long after the ice had gone off the lake. There had not been a lot of beachcombers yet because the weather was quite cold.